TI BQ28400 Battery Gas Gauge

The bq28400 monitors the battery temperature, capacity, voltage, current etc.
The device interface is I2C, its I2C slave 7-bit address is 0xb.
The device is usually embedded inside the "smart battery" pack.

Required properties:

 - compatible : Must be "ti,bq28400-battery" or "ti,bq30z55-battery"
 - reg : I2C Address must be 0xb.
 - ti,temp-cold : Cold temperature limit in celsius degree
 - ti,temp-hot : Hot temperature limit in celsius degree

Example:
	i2c@f9967000 {
		battery@b {
			compatible = "ti,bq28400-battery", "ti,bq30z55-battery";
			reg = <0xb>;
			ti,temp-cold = <2>;
			ti,temp-hot = <43>;
		};
	};

